1. Field of the Invention
The present invention relates to POS systems used in volume retail stores such as supermarkets, department stores, specialty stores, and the like, and more particularly to a POS system having a novel configuration that facilitates the process of canceling or correcting transaction data once registered at a POS terminal used as an electronic cash register.
2. Description of the Related Art
At a volume retail store, such as a supermarket, a department store, a specialty store, or the like, sales transactions are handled using a POS system which includes usually one store server and a plurality of POS terminals. A customer who wishes to purchase a product takes the product to a nearby POS terminal (cash register) in the store. The sales clerk (operator) enters the details of the purchased product into the POS terminal to register the transaction, and issues a receipt describing the details of the purchase and hands it over to the customer.
There is, however, the possibility that the operator may make an input error when entering the data on the purchased product into the POS terminal. If the operator notices the error while entering the data into the POS terminal, the details of the transaction can be easily corrected, for example, by deducting the erroneously entered price and re-entering the correct value.
However, when the customer notices the error after the receipt is issued to the customer and the transaction completed, or when it becomes necessary to correct the transaction data, for example, as a result of the purchase being returned by the customer, the transaction itself must be canceled and the correct data must be re-entered. This operation cannot be performed at POS terminals other than the POS terminal that registered the original transaction, that is, the POS terminal that issued the receipt for the purchased product.
This is because each POS terminal has a means of its own for recording a sales history, so that if the correction was made at a POS terminal other than the POS terminal used to register the sale, a discrepancy would occur in the amount of sales registered at that terminal.
FIG. 1 is a block diagram showing the configuration of a prior art POS terminal, FIG. 2 is a flowchart illustrating the processing performed at the POS terminal for the cancellation of a sales transaction, and FIG. 3 is a diagram showing data flows between the store server (SV) and the POS terminal (i) from which the cancellation operation is performed.
As shown in FIG. 1, the prior art POS terminal comprises a product transaction data input means 1, a transaction log means 2, a cancellation input means 3, an electronic message transmitting means 4 and electronic message receiving means 5 for transmitting and receiving electronic messages to and from the store server (not shown), a printing means 6, and a screen display means 7; the above-listed means are controlled by a task manager 8. The POS terminal further includes a transaction log file 9 for recording the results of the operations performed by the transaction log means 2 and the cancellation input means 3.
As shown in the flowchart of FIG. 2, to cancel a transaction at the POS terminal, first a cancel key is operated in step S1, the transaction serial number TR(n) of the receipt for the transaction to be canceled is entered in step S2, and a register key is operated in step S3 to determine the initiation of the cancellation operation. With the operation of the register key, the details of the transaction corresponding to the transaction serial number TR(n) are displayed on the screen of the display or the like (step S4); then, while viewing the screen, the operator determines whether the contents of the transaction serial number TR(n) match the contents of the receipt that is to be canceled (step S5).
When both contents match (Yes in step S5), a total key is operated (S6) to execute the cancellation operation (S7). If the answer is No in step S5, an abort key is operated (S8) to abort the cancellation operation.
While the series of operations shown in FIG. 2 is being performed at the POS terminal (i), data transfers such as shown in FIG. 3 are performed between the POS terminal (i) and the store server. First, when the operator (cashier) of the POS terminal (i) performs a transaction entering operation, and a transaction thus occurs at the POS terminal (i), transaction data TRi is written to the transaction log file (F(TRi)) maintained in the POS terminal (i) and, at the same time, a transaction data occurrence notification (Gen [POS(i), TR(n)]) is sent in the form of an electronic message to the store server, where the transaction data is written to a POS-by-POS transaction log file (FSTR).
Next, the operator notices an input error and saves the receipt (RCT [TR(n)]). When the flow of customers ceases, the operator (Ci) initiates the cancellation operation by referring to the receipt (RCT [TR(n)]). That is, the transaction log file is searched to retrieve the transaction data (GEN [TR(n)]), which is presented for display on the display screen (RES [TR(n)]). The operator (Ci) checks the displayed transaction data against the receipt and, if their contents match, operates the total key and writes the contents to the transaction log file F(TRi).
At the same time, a transaction data cancellation notification VOID [POS(i), TR(n)] is sent to the store server for writing to the POS-by-POS transaction log file.
As described above, in the prior art POS system, since the transaction data is stored in the POS terminal TR(i) that registered the transaction, if the transaction is to be canceled, the cancellation operation has had to be performed at that POS terminal TR(i).
However, in busy hours, for example, during the year end season when many customers line up in front of the cash register, if the sales data has to be corrected and re-entered by taking the receipt to the POS terminal where the sale was registered, it not only would involve a very cumbersome procedure for both the operator and the customer, but could also lead to errors when re-entering the data.
In view of this, it is traditionally practiced to accept a return from a customer or a request for correction of an erroneous input, for example, at a service counter or the like, and to issue to a correct receipt carrying the correct amount billed. The cancellation operation at the responsible POS terminal is performed at a later time, for example, when the POS terminal is not in use, or after the store is closed for the day. Customer convenience is thus given higher priority than the cancellation operation to be performed at the POS terminal. The cancellation operation is necessary to compute the total amount of sales registered at the POS terminal and totalize the sales for the entire store, but this is of no interest to the customer.
However, when the cancellation operation at the POS terminal is performed at a later time than the occurrence of the event requiring the cancellation operation, or after the store is closed for the day, the total amount of sales being reported at regular intervals of time during store hours does not reflect the actual sales figures. Furthermore, since it is necessary to provide a special counter such as a service counter, assign staff to the counter, and install a machine that can issue receipts, these provisions impose a great burden on relatively small supermarkets and other retail stores.
Furthermore, when correcting a transaction record for such reasons as a receipt input error or a returned product, since the transaction itself has had to be canceled once and correct transaction data has had to be re-entered for each product item, there has been the problem that re-entering data not only takes time but tends to incur input errors.
Accordingly, in the case of a POS system constructed from a plurality of POS terminals, there is a need for a POS system that allows corrections to be made to transactions from any POS terminal other than the POS terminal through which the transaction to be canceled or corrected was registered, that is, through which the purchase was registered. There is also a need for a POS system that allows transaction data to be canceled or corrected by correcting only necessary product data items, without having to cancel the entire data concerning that transaction.